1. Field of the Invention
The present invention relates to a mixer for capsule for dental restoration material to be used for rendering a mixing compartment in vacuo to mix a powder component and a liquid component with each other in a good state where the mixture does not substantially contain air bubbles, in a capsule for dental restoration material accommodating therein two components of definite amounts of previously weighed power component and liquid component in an isolated state from each other, each constituting a dental restoration material used for filling, cementing, lining and other applications in restoration of a tooth in the dental remedy field.
2. Description of the Conventional Art
In general, a dental restoration material is used for restoration of a tooth, such as filling, cementing and lining. As the dental restoration material, a two-component system material comprising a powder component and a liquid component, which are reacted with each other upon mixing, is usually used. Hitherto, this two-component system dental restoration material was provided for use after appropriately weighing the powder component and the liquid component every time and mixing them with each other. However, in recent years, for the purposes of omitting a weighing work of the powder component and the liquid component and a work for accommodating the dental restoration material after mixing in a syringe for administering it to a site to be restored, there have been developed capsules for dental restoration material, in which definite amounts of the powder component and the liquid component are previously weighed and accommodated in an isolated state from each other, the isolated state is released at a desired time, the both components are mechanically mixed with each other by shaking in a mixer, and the resulting mixture is extruded and administered directly to a site to be restored, such as a tooth cavity, through a nozzle.
As such capsules for dental restoration material, various capsules have been proposed. For example, in a capsule as disclosed in Japanese Patent examined Publication No. 38853/1991, the powder component of the two components is accommodated in a mixing compartment of a capsule main body, and the other liquid component is charged in a pillow formed of a sheet film, which is assembled in a side portion of the mixing compartment accommodating the pillow by means of a clip. Further, a two-component system capsule for mixing and discharge as disclosed in Japanese Patent Laid-Open No. 268555/1987 takes a configuration in which the powder component of two components is accommodated in a mixing compartment within a capsule main body, and the other liquid component is accommodated in a pillow formed of a sheet film comprising a resin, a metal foil, or a laminate of a resin and a metal foil. In any of the capsules having such configurations, when the dental restoration material comprising two components of definite amounts of the previously weighed powder component and liquid component is mixed by shaking in a mixer, air present in the mixing compartment mingles into the mixture, whereby it exists as air bubbles. For this reason, the dental restoration material administered in a dental restoration site such as a cavity of a patient contains the air bubbles, so that these conventional capsules involved various problems including a reduction in the strength and a change in the color tone with respect to the dental restoration material.
Thus, in order to overcome the problems of the conventional capsules for dental restoration material as described above and to prevent the occurrence of a phenomenon in which, during mixing the dental restoration material comprising two components of definite amounts of the previously weighed powder component and liquid component accommodated in the conventional capsule for dental restoration material, air present in the mixing compartment mingles into the resulting mixture, whereby it exists as air bubbles, we, the present inventors proposed in Japanese Patent Application No. 163408/2000 a capsule for dental restoration material in which an air-permeable filter capable of ventilating air within the mixing compartment out the mixing compartment without passing the powder component and the liquid component through is provided in at least a part of a peripheral wall of the mixing compartment.
Also, the present inventors developed and proposed a mixer for capsule for dental restoration material suitable as a unit for mixing with respect to the capsule for dental restoration material in which an air-permeable filter capable of ventilating air within the mixing compartment out the mixing compartment without passing the powder component and the liquid component through is provided in at least a part of a peripheral wall of the mixing compartment, as disclosed in Japanese Patent Application No. 163593/2000.
This mixer for capsule for dental restoration material is a mixer for capsule for dental restoration material to be used for mixing the powder component and the liquid component of the dental restoration material by shaking within the mixing compartment of the capsule for dental restoration material in which an air-permeable filter capable of ventilating out air is provided as an external wall constituting at least a part of the peripheral wall, and has a configuration in which a capsule holding compartment for holding the capsule for dental restoration material in a portion other than the position corresponding to the air-permeable filter is provided, the capsule holding compartment being connected to a vacuum device. According to such configuration, when the powder component and the liquid component are mixed with each other by shaking, while rendering the mixing compartment in vacuo, the mixture becomes a dental restoration material in a good state where no air bubbles exist and can be administered directly to a site to be restored, such as a tooth cavity of a patient.
However, since this mixer for capsule for dental restoration material has a configuration in which the powder component and the liquid component are mixed with each other by shaking through a reciprocating motion while rendering the mixing compartment of the capsule for dental restoration material held in the capsule holding compartment in vacuo, a very large noise is generated during shaking the capsule holding compartment. Further, since it has a configuration in which the powder component and the liquid component within the mixing compartment of the capsule for dental restoration material are mixed with each other by reciprocating the capsule holding compartment, it takes a considerable time to mix the powder component and the liquid component within the mixing compartment in a good state. If the reciprocating speed of the capsule holding compartment is increased in order to shorten this time, the noise becomes larger.
The present invention is aimed to overcome the above-described defects of the conventional art and to provide a mixer for capsule for dental restoration material which generates a smaller noise during mixing a powder component and a liquid component within a mixing compartment of a capsule for dental restoration material and from which a dental restoration material in a good state where no air bubbles exist in the resulting mixture can be obtained within a short period of time and with a good efficiency.
In order to achieve the above-described aim, the present inventors made extensive and intensive investigations. As a result, it has been found that when a capsule holding compartment for holding a capsule for dental restoration material such that air can be discharged out from an air-permeable filter is kept in a constant direction with respect to the longitudinal direction thereof, and the capsule holding compartment itself is subjected to a circular motion in this state, during mixing a powder component and a liquid component within a mixing compartment of the capsule for dental restoration material, not only a noise generated during mixing is small, but also a dental restoration material in a good state where no air bubbles exist in the resulting mixture can be obtained within a short period of time and with a good efficiency, leading to accomplishment of the invention.
Specifically, the present invention is concerned with a mixer for capsule for dental restoration material to be used for mixing a powder component and a liquid component of a dental restoration material within a mixing compartment of a capsule for dental restoration material having an air-permeable filter, which does not pass the powder component and the liquid component through but can ventilate out air within the mixing compartment, placed in a site connecting the inside of the mixing compartment to the outside, the mixer comprising a capsule holding compartment for holding the capsule for dental restoration material such that the air within the mixing compartment can be discharged out from the air-permeable filter, a rotating unit of capsule holding compartment for subjecting the capsule holding compartment itself to a circular motion in the state that a longitudinal direction of the capsule holding compartment is kept in a constant direction, a driving unit for driving the rotating unit of capsule holding compartment, and a vacuum device connected to the capsule holding compartment.
Further, it has been found to be preferable that, when the rotating unit of capsule holding compartment is constituted of a rotating table that is pivoted rotatably to a fixed axis and is rotated by the driving unit, an axis for capsule holding compartment that is pivoted rotatably to the rotating table in a position far from the fixed axis by a predetermined distance and has the capsule holding compartment fixed thereto, and a rotation power transmitting unit for connecting the fixed axis to the axis for capsule holding compartment such that when the axis for capsule holding compartment goes a round centering the fixed axis, the axis for capsule holding compartment makes one revolution, the capsule holding compartment itself can be subjected to a smooth circular motion in the state that the longitudinal direction of the capsule holding compartment is kept in a constant direction.
Moreover, it has been found to be preferable that, when the driving unit is controlled by a driving control unit for making its rotation number and/or rotation time variable, or when the vacuum device is provided with a vacuum control unit for controlling a decompression degree and/or a decompression time, since the rotation number and/or the rotation time, or the decompression degree and/or the decompression time of the capsule holding compartment can be controlled to be in a suitable condition depending on the dental restoration material comprising various kinds of the powder component and the liquid component to be mixed, or on the quantity of the dental restoration material to be mixed, not only a failure by over-mixing or short-mixing during the mixing works can be prevented, but also a dental restoration material in a good state can be easily obtained only through a simple operation by an operator to set up a suitable condition.
In addition, it has been found to be preferable that, when the vacuum device and the capsule holding compartment are connected to each other by a passage respectively provided in the fixed axis, the rotating table and the axis for capsule holding compartment, not only the air within the capsule holding compartment can be stably discharged out, but also the durability of the whole of the apparatus of the present invention increases; and that, when the vacuum device is an ejector connected to a compressed air supply device of dental unit, since the compressed air supply device of dental unit that is placed in a dental clinic can be used as a power source as it stands, the configuration of the apparatus of the present invention can be made inexpensive and simple.